Hydrogen storage composition, hydrogen storage container and method for producing hydrogen storage container with hydrogen storage composition

ABSTRACT

A hydrogen storage composition, a hydrogen storage container and a method for producing the hydrogen storage container are provided. The hydrogen storage composition includes a thermally-conductive material, a hydrogen storage material, and optionally a granular elastic material. The hydrogen storage container includes a canister body and the hydrogen storage composition. After the hydrogen storage composition is placed into a canister body, a vacuum environment within the canister body is created, and a first weight of the canister body is recorded. Then, hydrogen gas is charged into the canister body, and a second weight of the canister body is recorded. Then, a hydrogen storage amount is calculated according to the first weight and the second weight. If the hydrogen storage amount reaches the predetermined value, the hydrogen storage container is produced.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation-in-part application of U.S. patentapplication Ser. No. 15/296,647 filed on Oct. 18, 2016, and entitled“HYDROGEN STORAGE COMPOSITION, HYDROGEN STORAGE CONTAINER AND METHOD FORPRODUCING HYDROGEN STORAGE CONTAINER WITH HYDROGEN STORAGE COMPOSITION”,the entirety of which is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a composition and a method forproducing a container, and more particularly to a hydrogen storagecomposition comprising a thermally-conductive material, a hydrogenstorage material and a granular elastic material. The present inventionalso relates to a hydrogen storage container with the hydrogen storagecomposition and a method for producing the hydrogen storage containerwith the hydrogen storage composition.

BACKGROUND OF THE INVENTION

The byproduct of using the hydrogen energy is water. Consequently, theuse of the hydrogen energy has many benefits such as high environmentalprotection and low pollution. Because the hydrogen energy is clean andsafe and the use of the hydrogen energy reduces emission of thegreenhouse gas and air pollution, the hydrogen energy source isconsidered as one of the secondary energy sources that replace fossilfuels. Therefore, the development and application of hydrogen energy arehighly valued in recent years. However, the technology of storinghydrogen gas (i.e., a hydrogen storing technology) is a challenge topromote and use the hydrogen source.

Nowadays, two methods are widely used to the store hydrogen gas. Thefirst method adopts a high pressure storing technology. For example,after the hydrogen gas is pressurized, the pressurized hydrogen gas ischarged into a container (e.g., a steel cylinder) and stored in thecontainer. Alternatively, after the hydrogen gas is liquefied, theliquefied hydrogen is stored in the container. As known, the way ofstoring the pressurized hydrogen gas or the liquefied hydrogen needshigh operating cost and bulky container and has safety problem (e.g.,gas leakage).

The second method adopts a low pressure storing technology. For example,the hydrogen gas is absorbed on a hydrogen storage material throughchemical bonding. Since the internal pressure of the hydrogen storagecontainer is lower, this storing method is safer. Moreover, the hydrogenstorage density is high and the container is small. Consequently, themanufacturers make efforts in developing the novel hydrogen storagematerials. However, as the hydrogen gas is absorbed by the hydrogenstorage material or desorbed from the hydrogen storage material, thevolume expansion or shrinkage is at a ratio from 1% to 30%. The volumeexpansion or shrinkage usually results in stress. The stress results ina strain of the hydrogen storage container (e.g., a hydrogen storagecanister). In other words, the durability of the canister body of thehydrogen storage container is deteriorated.

For reducing deformation of the canister body of the hydrogen storagecontainer during the process of charging the hydrogen gas to thehydrogen storage material, some methods were disclosed. For example, inthe production process of the hydrogen storage canister, the hydrogenstorage material is poured into plural aluminum boxes, then the pluralaluminum boxes are stacked on each other, and finally the neckingprocedure is performed. After the aluminum boxes with the hydrogenstorage material are sequentially placed into the canister body, it isnecessary to perform two thermally-treating processes on the canisterbody. Since the process of sequentially placing the aluminum boxes intothe canister body and thermally-treating processes are troublesome,time-consuming, labor-intensive, costly and power-consuming, thefabricating cost of the hydrogen storage canister cannot be reduced.

Therefore, the present invention provides a hydrogen storagecomposition, a hydrogen storage container and a method for producing ahydrogen storage container with the hydrogen storage composition inorder to solve the above drawbacks.

SUMMARY OF THE INVENTION

An object of the present invention provides a hydrogen storagecomposition for alleviating the deformation that is resulted from thevolume expansion or shrinkage of the hydrogen storage material andconfigured to conduct heat among the hydrogen storage materials and thecanister body. In addition, the hydrogen storage composition is obtainedby mixing directly in a specific ratio to obtain the optimized packingdensity. The displacement of the hydrogen storage composition can bealleviated during the process of charging or discharging the hydrogengas. Consequently, the durability and safety of the canister body areenhanced.

Another object of the present invention provides a hydrogen storagecontainer with the hydrogen storage composition of the presentinvention. The hydrogen storage composition includes a hydrogen storagematerial, a granular elastic material and optionally athermally-conductive material directly mixed together and physicallycombined together. It is easy to place the hydrogen storage compositioninto the canister body. Furthermore, each of the hydrogen storagematerial, the granular elastic material and the thermally-conductivematerial are removable from the hydrogen storage composition by sieving.Thus, the relative ratio of the hydrogen storage material, the granularelastic material and the thermally-conductive material is adjustable.While the relative ratio of the hydrogen storage composition has to beenadjusted, the hydrogen storage container with the hydrogen storagecomposition can be reworked easily.

A further object of the present invention provides a method forproducing a hydrogen storage container in cost-effective,material-saving, labor-saving and time-saving manners. Since, thehydrogen storage composition including the hydrogen storage material,the granular elastic material and the thermally-conductive materialmixed with each other directly and physically combined together, it iseasy to place the hydrogen storage composition into the canister body.In addition, since the relative ratio of hydrogen storage container withthe hydrogen storage composition is adjustable, it is easy rework andadjust the relative ratio placed in the canister body.

In accordance with an aspect of the present invention, there is provideda hydrogen storage composition. The hydrogen storage compositionincludes a hydrogen storage material, a granular elastic material andoptionally a thermally-conductive material. The granular elasticmaterial is mixed with the hydrogen storage material and configured toalleviate a deformation that is resulted from a volume expansion orshrinkage of the hydrogen storage material. The thermally-conductivematerial is mixed with the hydrogen storage material and the granularelastic material and configured to conduct heat among the hydrogenstorage material and alleviate a displacement of the granular elasticmaterial relative to the hydrogen storage material.

In accordance with another aspect of the present invention, there isprovided a hydrogen storage container. The hydrogen storage compositionincludes a hydrogen storage material, a granular elastic material andoptionally a thermally-conductive material. The granular elasticmaterial is mixed with the hydrogen storage material and configured toalleviate a deformation that is resulted from a volume expansion orshrinkage of the hydrogen storage material. The thermally-conductivematerial is mixed with the hydrogen storage material and the granularelastic material and configured to conduct heat among the hydrogenstorage material and the canister body, and alleviate a displacement ofthe granular elastic material relative to the hydrogen storage material.

In accordance with a further aspect of the present invention, there isprovided a method for producing a hydrogen storage container. The methodincludes the following steps. In a step (a), a hydrogen storagecomposition is placed into a canister body. The hydrogen storagecomposition includes a hydrogen storage material, a granular elasticmaterial and a thermally-conductive material. The granular elasticmaterial is mixed with the hydrogen storage material and configured toalleviate a deformation that is resulted from a volume expansion orshrinkage of the hydrogen storage material. The thermally-conductivematerial is mixed with the hydrogen storage material and the granularelastic material and configured to conduct heat among the hydrogenstorage material and the canister body, and alleviate a displacement ofthe granular elastic material relative to the hydrogen storage material.In a step (b), a vacuum environment within the canister body is created,and a first weight of the canister body is recorded. In a step (c),hydrogen gas is charged into the canister body to activate the hydrogenstorage material, and a second weight of the canister body is recorded.In a step (d), a hydrogen storage amount is calculated according to thefirst weight and the second weight. If the hydrogen storage amountreaches the predetermined value, the hydrogen storage container isproduced. If the hydrogen storage amount does not reach thepredetermined value, the steps (b), (c) and (d) are repeatedly done.

The above contents of the present invention will become more readilyapparent to those ordinarily skilled in the art after reviewing thefollowing detailed description and accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a detailed diagram of the hydrogen storage composition anembodiment of the present invention;

FIG. 2 is a flowchart illustrating a process of forming and pretreatinga hydrogen storage composition according to an embodiment of the presentinvention;

FIG. 3 is a flowchart illustrating a method for producing a hydrogenstorage container according to an embodiment of the present invention;

FIG. 4 schematically illustrates some positions of measuring thedeformation of the hydrogen storage container according to an embodimentof the present invention; and

FIG. 5 is a plot illustrating the hydrogen desorption curves of fourhydrogen storage compositions.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will now be described more specifically withreference to the following embodiments. It is to be noted that thefollowing descriptions of preferred embodiments of this invention arepresented herein for purpose of illustration and description only. It isnot intended to be exhaustive or to be limited to the precise formdisclosed.

FIG. 1 shows a detailed diagram of the hydrogen storage composition anembodiment of the present invention. According to the present invention,a hydrogen storage composition 1 is provided. The hydrogen storagecomposition is filled in a canister body 30 of a hydrogen storagecontainer 3 (see FIG. 4). In an embodiment, the hydrogen storagecomposition 1 comprises a hydrogen storage material 11, a granularelastic material 12 and a thermally-conductive material 13. The hydrogenstorage material 11, the granular elastic material 12 and thethermally-conductive material 13 are mixed with each other by forexample a physical mixing method. Namely, the hydrogen storagecomposition 1 is a mixture of pure separable states, wherein thehydrogen storage material 11, the granular elastic material 12 and thethermally-conductive material 13 are separable by physicalclassification. The granular elastic material 12 is optionallyconfigured to alleviate a deformation that is resulted from a volumeexpansion or shrinkage of the hydrogen storage material 11. Thethermally-conductive material 13 is configured to conduct heat among thehydrogen storage material 11 and the canister body 30, and alleviate adisplacement of the granular elastic material 12 relative to thehydrogen storage material 11. In the embodiment, the diameter of thehydrogen storage material 11 can be for example ranged from 30 μm to 900μm. For alleviating the deformation, the granular elastic material 12can have an average diameter about 1000 μm to 3000 μm which is largerthan that of the hydrogen storage material 11. In addition, forconducting the heat and alleviating the displacement, thethermally-conductive material 13 can be for example strip-like orneedle-like and have the length for example ranged from 1500 μm to 9900μm and the cross-sectional diameter ranged from 50 μm to 250 μm. It isnoted that the length of the thermally-conductive material 13 is largerthan the diameter of the granular elastic material 12. The weightfraction of the thermally-conductive material 13 is preferably 1 to 15weight parts, more preferably 1 to 10 weight parts, and the mostpreferably 1 to 5 weight parts, based on a total of 100 weight parts ofthe thermally-conductive material 13, the hydrogen storage material 11and the granular elastic material. In case that the fraction of thethermally-conductive material 13 is higher than 1 weight part, thethermally-conductive material 13 can conduct heat to the hydrogenstorage material 11 and alleviate the displacement of the granularelastic material 12 relative to the hydrogen storage material 11. Incase that the fraction of the thermally-conductive material 13 is lowerthan 30 weight part, the thermally-conductive material 13 can conductheat to the hydrogen storage material 11 thoroughly in order toeffectively heat or cool the hydrogen storage material 11. In themeantime, the displacement of the granular elastic material 12 relativeto the hydrogen storage material 11 is alleviated. Consequently, theefficiency of charging/discharging hydrogen gas is increased and thedurability and safety of the canister body 30 are enhanced. The fractionof the granular elastic material 12 is preferably 1 to 35 weight parts,more preferably 1 to 20 weight parts, and the most preferably 1 to 10weight parts, based on a total of 100 weight parts of thethermally-conductive material 13, the hydrogen storage material 11 andthe granular elastic material 12. In case that the fraction of thegranular elastic material 12 is higher than 1 weight part, the granularelastic material 12 can alleviate the strain or deformation that isresulted from the volume expansion or shrinkage of the hydrogen storagematerial 11. In case that the fraction of the granular elastic material12 is lower than 35 weight part, the fraction of the hydrogen storagematerial 11 is at least 50 weight parts in order to increase thehydrogen storage amount of the hydrogen storage container. It is notedthat the fraction of the hydrogen storage material 11, the granularelastic material 12 and the thermally-conductive material 13 can beadjustable according to the practical requirements and obtain that anoptimized packing density of the hydrogen storage composition 1, and notredundantly described herein.

The cross section of the canister body 30 has a circular shape, anelliptic shape, a triangular shape, a square shape, a polygonal shape oran irregular shape. It is noted that the shape of the cross section ofthe canister body 30 is not restricted. In an embodiment, the canisterbody 30 is a cylinder-shaped canister body. Preferably but notexclusively, the hydrogen storage container 3 is made of a metallicmaterial (e.g., steel or aluminum alloy) or a carbon fiber-reinforcedcomposite material. Moreover, the container 3 is a gas storage canisteror a hydrogen storage canister. The hydrogen storage container 3 issuitably used as a hydrogen gas source. Moreover, the hydrogen storagecontainer 3 is applied to any electronic device using fuel cells. Anexample of the electronic device includes but is not limited to a mobileelectric vehicle, a stationary power generator or a 3C product. Thehydrogen storage container 3 has an accommodation space foraccommodating the hydrogen storage composition 1 and storing thehydrogen gas.

An example of optionally the thermally-conductive material 13 includesbut is not limited to carbon, copper, titanium, zinc, iron, vanadium,chromium, manganese, cobalt, nickel or aluminum, an alloy wire, a fiberyarn, a needle-like structure or a strip: like structure of the abovecomponents, or any other appropriate thermally-conductive material 13with thermal conductivity in the range between 90 W/mk and 500 W/mk. Dueto the thermal conductivity of the alloy wire, the fiber yarn or theneedle-type structure, the surface area of the thermally-conductivematerial 13 is effectively increased and the thermal conduction efficacyof the hydrogen storage material 11 is enhanced. Furthermore, the lengthof the thermally-conductive material 13 is larger than the diameter ofthe granular elastic material 12. It facilitates thethermally-conductive materials 13 to alleviate the displacement of thegranular elastic material 12 relative to the hydrogen storage material11 during the charging/discharging process.

In the embodiment, the hydrogen storage material 11 is optionally ahydrogen storage alloy or a hydrogen storage nanomaterial. The hydrogenstorage material 11 can absorb or desorb hydrogen gas at differentoperating temperatures and pressures in order to achieve the purpose ofstoring or releasing the hydrogen gas. In an embodiment, the hydrogenstorage material 11 includes an AB alloy, an A2B alloy, an AB2 alloy, anAB5 alloy or a body-centered cubic (BCC) alloy. In the AB5 alloy, A islanthanum (La) alone or the mixture of at least one rare earth elementand lanthanum. Particularly, lanthanum (La) or a portion of lanthanum(La) is substituted by cerium (Ce), praseodymium (Pr), neodymium (Nd) orother rare-earth element. For example, A is a cerium-rich alloy (Mm).Moreover, B is iron (Fe), nickel (Ni), manganese (Mn), cobalt (Co) oraluminum (Al). In the AB2 alloy, A is titanium (Ti) or zirconium (Zr), Bis manganese (Mn), chromium (Cr), vanadium (V) or iron (Fe), and theratio of A to B is in the range between 1:1 and 1:2 (e.g., 1:2). Forexample, the AB alloy includes titanium-iron (TiFe) alloy ortitanium-cobalt (TiCo) alloy, wherein the B component can be partiallysubstituted by a variety of elements. For example, the A2B ismagnesium-nickel alloy (Mg2Ni). The BCC alloy is a body-centered cubicalloy consisting of titanium (Ti), chromium (Cr), vanadium (V),molybdenum (Mo) and the like. Preferably, the hydrogen storage materialincludes but is not limited to lanthanum-nickel alloy series,iron-titanium alloy series or magnesium-nickel alloy series. Inaddition, the carbon nanomaterial is also suitably used as the hydrogenstorage material 11.

An example of optionally the granular elastic material 12 includes butis not limited to an elastic resin, or a solid polymeric materialselected from the group consisting of polyurethane (PU), rubber,elastomer, poly vinyl chloride (PVC), acrylonitrile-butadiene-styrenecopolymer (ABS copolymer), high density polyethylene (HDPE), low densitypolyethylene (LDPE), polystyrene (PS), polycarbonate (PC), poly (methylmethacrylate) (PMMA), thermoplastic elastomer (TPE) and polypropylene(PP). Preferably, the elastic material is polyurethane (PU). Thegranular elastic material 12 is used for alleviating the deformation ofthe hydrogen storage material 11 from volume expansion or shrinkage.More preferably, the granular elastic material 12 can be for example aPU granule. It is noted that the granular elastic material 12 is notlimited to the above-mentioned materials. Preferably, the granularelastic material 12 includes a solid polymeric material having adeformation ratio higher than or equal to the deformation ratio of thehydrogen storage material 11. Consequently, the granular elasticmaterial 12 can alleviate the strain or deformation that is resultedfrom the volume expansion or shrinkage of the hydrogen storage material11.

FIG. 2 is a flowchart illustrating a process of forming and pretreatinga hydrogen storage composition according to an embodiment of the presentinvention. The structures, elements and functions of the hydrogenstorage composition 1 are similar to those of the hydrogen storagecomposition 1 in FIG. 1, and are not redundantly described herein. In astep S11, a thermally-conductive material 13 and a granular elasticmaterial 12 are mixed and placed into a pretreatment vessel (not shown),and then the pretreatment vessel is sealed. Consequently, thepretreatment vessel is in an airtight state. Then, in a step S12, avacuum environment within the pretreatment vessel is created. Forexample, after the pretreatment vessel with the thermally-conductivematerial 13 and the granular elastic material 12 is placed in a constanttemperature water tank and maintained at a constant temperature, avacuum pump (not shown) is turned on to create the vacuum environmentwithin the pretreatment vessel. Preferably but not exclusively, theconstant temperature water tank is maintained at 60° C. or higher, andthe vacuum pump is operated for at least one hour to create the vacuumenvironment within the pretreatment vessel. In a step S13, thethermally-conductive material 13 and the granular elastic material 12are removed from the pretreatment vessel and mixed with a hydrogenstorage material 11, and the thermally-conductive material 13, thegranular elastic material 12 and the hydrogen storage material 11 arestirred for a specified time period (e.g., the stirring time includesbut is not limited to 5 minutes) and uniformly mixed. Consequently, theprocess of forming and pretreating the hydrogen storage composition 1 iscompleted.

FIG. 3 is a flowchart illustrating a method for producing a hydrogenstorage container according to an embodiment of the present invention.Firstly, in a step S21, the hydrogen storage composition 1 is placedinto a canister body 30. In an embodiment, the hydrogen storagecomposition 1 (see FIG. 1) comprises a thermally-conductive material 13,a hydrogen storage material 11 and a granular elastic material 12 in aspecified weight ratio. The fraction of the thermally-conductivematerial 13 is preferably 1 to 15 weight parts, and the fraction of thegranular elastic material 12 is preferably 1 to 35 weight parts, basedon a total of 100 weight parts of the thermally-conductive material 13,the hydrogen storage material 11 and the granular elastic material 12.Optionally, the step S21 further comprises a sub-step of pretreating thehydrogen storage composition 1. The way of pretreating the hydrogenstorage composition 1 is similar to the flowchart of FIG. 2. That is,after the thermally-conductive material 13 and the granular elasticmaterial 12 are mixed in the pretreatment vessel, a vacuum environmentwithin the pretreatment vessel is created. Then, the hydrogen storagematerial 11 is added and uniformed mixed with the thermally-conductivematerial 13 and the granular elastic material 12, and thus the hydrogenstorage composition 1 is formed. After the hydrogen storage composition1 is formed and placed into a canister body 30, the canister body 30 issealed. Consequently, the canister body 30 is in an airtight state.

Then, in a step S22, a vacuum environment within the canister body 30 iscreated, and the weight of the canister body 30 is recorded. The weightof the canister body 30 indicates the weight of the canister body 30before the canister body 30 is charged with hydrogen gas. In anembodiment of the step S22, after the canister body 30 is in theairtight state, the canister body 30 is placed in a constant temperaturewater tank and maintained at a constant temperature, and a vacuum pump(not shown) is turned on to create the vacuum environment within thecanister body 30. Preferably but not exclusively, the constanttemperature water tank is maintained at 60° C. or higher.

Then, in a step S23, hydrogen gas is charged into the canister body 30to activate the hydrogen storage material 11, and the weight of thecanister body 30 is recorded. The weight of the canister body 30indicates the weight of the canister body 30 after the canister body 30is charged with hydrogen gas. In an embodiment, for charging hydrogengas into the canister body 30, the canister body 30 is placed in ahydrogen supply system with cold water circulation (5° C.˜20° C.) andpure hydrogen gas is charged into the canister body 30 at a pressure of1 MPa for at least one hour. The process of charging hydrogen gas intothe canister body may be varied according to the practical requirements.

Then, in a step S24, a hydrogen storage amount is calculated accordingto the result of comparing the weight of the canister body 30 beforecharged with hydrogen gas and the weight of the canister body 30 aftercharged with hydrogen gas. Then, a step S25 is performed to judgewhether the hydrogen storage amount reaches a predetermined value. Ifthe judging condition of the step S25 is satisfied, it means that thehydrogen storage container is produced. Whereas, if the judgingcondition of the step S25 is not satisfied, the above steps arerepeatedly done until the hydrogen storage amount reaches thepredetermined value. It is noted that the hydrogen storage material 11,the granular elastic material 12 and the thermally-conductive material13 are directly mixed with each other by a physical mixing method. Thegranular elastic material 12 is not further heated for curing or forminga fixed block. It is noted that the hydrogen storage composition 1 is amixture of pure separable states. The hydrogen storage material 11, thegranular elastic material 12 and the thermally-conductive material 13are separable by physical classification. Namely, the hydrogen storagecomposition 1 is reworkable. While the relative ratio of the hydrogenstorage composition 1 has to be adjusted, the hydrogen storage container3 with the hydrogen storage composition 1 can be reworked easily.

The present invention will be further understood in more details withreference to the following examples.

Four formulations of the hydrogen storage compositions 1 are prepared bymixing different amounts of thermally-conductive material 13 (e.g.,aluminum fiber), a fixed amount of granular elastic material 12 (e.g.,PU granule) and a fixed amount of hydrogen storage material 11. After 50grams of thermally-conductive material 13, 70 grams of granular elasticmaterial 12 and 3000 grams of hydrogen storage material 11 are mixed, aformulation A is prepared. After 100 grams of thermally-conductivematerial 13, 70 grams of granular elastic material 12 and 3000 grams ofhydrogen storage material 11 are mixed, a formulation B is prepared.After 150 grams of thermally-conductive material 13, 70 grams ofgranular elastic material 12 and 3000 grams of hydrogen storage material11 are mixed, a formulation C is prepared. After 200 grams ofthermally-conductive material 13, 70 grams of granular elastic material12 and 3000 grams of hydrogen storage material 11 are mixed, aformulation D is prepared. Then, the hydrogen storage compositions 1with the formulations A, B, C and D are placed into four differentcanister bodies 30, respectively. After the subsequent hydrogenactivating process and measuring process, four hydrogen storagecontainers 3 are produced. In addition, some experimental data areacquired for comparison.

Pretreatment of Hydrogen Storage Composition

Firstly, 50 grams of thermally-conductive material 13 and 70 grams ofgranular elastic material 12 are mixed and placed into a pretreatmentvessel. Then, the pretreatment vessel is sealed, and thus thepretreatment vessel is in an airtight state. Then, the pretreatmentvessel is placed in a constant temperature water tank and maintained at60° C. or higher. Then, a vacuum pump is turned on for at least one hourin order to create a vacuum environment within the pretreatment vessel.Then, the thermally-conductive material 13 and the granular elasticmaterial 12 are removed from the pretreatment vessel and poured into astirring device. Then, 3000 grams of hydrogen storage material 11 ispoured into the stirring device. The stirring device is operated for atleast 5 minutes to uniformly mix these components. Meanwhile, theprocess of forming and pretreating the hydrogen storage composition 1 iscompleted. Meanwhile, the formulation A is produced.

The processes of producing the formulations B, C and D are similar tothe process of producing the formulation A except for the weight of thethermally-conductive material 13. The processes of pretreating thehydrogen storage compositions 1 containing the formulations B, C and Dare similar to the process of pretreating the hydrogen storagecomposition containing the formulation A.

Production of Hydrogen Storage Container and Hydrogen Activation

The canister body 30 of the hydrogen storage container 3 is acylindrical canister body with the following dimensions. For example,the length is 297 mm, the diameter is 76.2 mm, and the wall thickness2.0 mm. Moreover, the designed pressure is 3.2 MPa.

Firstly, a canister body 30 is provided. The canister body 30 is sealedand contains at least one gas conducting element (e.g., a through-holeor a gas-penetrative pipe). Then, the formulation A after pretreatmentis placed into the canister body 30. Then, the airtight canister body 30is placed in a constant temperature water tank and maintained at 60° C.or higher. Then, a vacuum pump is turned on to create a vacuumenvironment within the canister body 30, and the weight of the canisterbody 30 is recorded. The weight of the canister body 30 indicates theweight of the canister body 30 before the canister body 30 is chargedwith hydrogen gas. Then, the canister body 30 is placed in a hydrogensupply system with cold water circulation (5˜20° C.) and pure hydrogengas is charged into the canister body 30 at a pressure of 1 MPa for atleast one hour. Consequently, hydrogen gas is charged into the canisterbody 30 to activate the hydrogen storage material 11. The weight of thecanister body 30 is recorded. The weight of the canister body 30indicates the weight of the canister body 30 after the canister body 30is charged with hydrogen gas. Then, a hydrogen storage amount iscalculated according to the result of comparing the weight of thecanister body 30 before charged with hydrogen gas and the weight of thecanister body 30 after charged with hydrogen gas. If the hydrogenstorage amount reaches the predetermined value, the hydrogen storagecontainer 3 is produced. If the hydrogen storage amount does not reachthe predetermined value, the above processes are repeatedly done untilthe hydrogen storage amount reaches the predetermined value.

The components of the formulations B, C and D are similar to thecomponents of the formulation A except for the weight of thethermally-conductive material 13 (e.g., aluminum fiber). The processesof producing the hydrogen storage container 3 containing theformulations B, C and D are similar to the process of producing thehydrogen storage container 3 containing the formulation A, and are notredundantly described herein.

Results of Experiment

As mentioned above, the four formulations A, B, C and D are prepared bymixing different amounts of thermally-conductive material 13 (e.g.,aluminum fiber), a fixed amount of granular elastic material 12 (e.g.,PU granule) and a fixed amount of hydrogen storage material 11. Thehydrogen storage amounts of the hydrogen storage containers containingdifferent formulations are listed in Table 1.

TABLE 1 Weight(g) Weight(g) hydrogen before charged with after chargedwith storage amount Formulation hydrogen hydrogen (g) A 3791.68 3839.7845.37 B 3840.39 3888.51 45.39 C 3873.72 3922.92 46.41 D 3952.87 4002.0646.35

Please refer to Table 1. As the fraction of the thermally-conductivematerial 13 increases, the hydrogen storage amount gradually increases.Moreover, in each formulation, the weight percentage of the hydrogenstorage amount of the hydrogen storage material 11 (i.e., the hydrogenstorage amount of the hydrogen storage container 3) with respect to theweight of the hydrogen storage material 11 is about 1.5%.

FIG. 4 schematically illustrates some positions of measuring thedeformation of the hydrogen storage container according to an embodimentof the present invention. For example, the deformation values at thepositions a, b, c, d, e and f of the canister body 30 are measured. Themeasuring results are listed in Table 2.

TABLE 2 Formula Before/after A B C D charged with hydrogen Before AfterBefore After Before After Before After Deformation a 76.35 76.38 76.176.1 76.2 76.2 76.1 76 measured b 76.1 76.38 76 76 75.9 75.8 76.1 75.95at c 76.32 76.28 76.05 76 75.95 75.9 76.15 76 different d 76.3 76.2876.2 76.25 76.25 76.25 75.85 76 positions e 76.32 76.42 76.3 76.3 76.2576.25 75.8 76.05 (mm) f 76.18 76.24 76.25 76.25 76.1 76.15 75.8 76.05

Please refer to Table 2 again. In the hydrogen storage container 3containing the formulation A, B, C or D, the deformation values measuredat different positions before charged with hydrogen gas and aftercharged with hydrogen gas are very small. In other words, the additionof the granular elastic material 12 can alleviate the deformation (orstrain) that is resulted from the volume expansion or shrinkage of thehydrogen storage material 11. Furthermore, there is no obviousdisplacement of the hydrogen storage material 11 with respect to thegranular elastic material 13 and thermally-conductive material 13. Sincethe deformation of the canister body 30 is reduced and the displacementsof the hydrogen storage composition 1 is avoided, the durability andsafety of the canister body 30 are enhanced.

FIG. 5 is a plot illustrating the hydrogen desorption curves of thehydrogen storage compositions 1 containing the formulations A, B, C andD. The experiments of acquiring the hydrogen desorption curves arecarried out in water (50° C.). Initially, hydrogen gas is dischargedfrom the hydrogen storage container 3 at the hydrogen desorption rate of8 liter/min. Until the hydrogen desorption rate is 0.5 liter/min, thedischarge of hydrogen gas is stopped. The hydrogen desorption curves ofthe hydrogen storage compositions 1 containing the formulations A, B, Cand D are shown in FIG. 5. The hydrogen storage composition 1 containingthe formulation A can discharge hydrogen gas at the hydrogen desorptionrate of 8 liter/min for 1300 seconds. The hydrogen storage composition 1containing the formulation B can discharge hydrogen gas at the hydrogendesorption rate of 8 liter/min for 2200 seconds. The hydrogen storagecomposition 1 containing the formulation C can discharge hydrogen gas atthe hydrogen desorption rate of 8 liter/min for 2900 seconds. Thehydrogen storage composition 1 containing the formulation D candischarge hydrogen gas at the hydrogen desorption rate of 8 liter/minfor 3200 seconds. The results of the experiments demonstrate that thehydrogen desorption duration increases with the increasing amount of thethermally-conductive material 13. Since the thermally-conductivematerial 13 has the strip-like structure, the thermal conductionefficacy of the hydrogen storage composition 1 is enhanced. Under thiscircumstance, the efficiency of discharging hydrogen gas, the dischargedamount of hydrogen gas and the hydrogen desorption duration increase.Since the thermally-conductive material 13, the hydrogen storagematerial 11 and the elastic material 12 of the hydrogen storagecomposition 1 are directly mixed with each other, the hydrogen storagecomposition 1 possesses the function of the aluminum boxes of theconventional technology. According to the present invention, the neckingprocedure is previously performed because it is not necessary to placethe aluminum boxes into the canister body 30. When compared with theconventional technology, the process of pouring the hydrogen storagematerial into plural aluminum boxes, the process of placing the aluminumboxes into the canister body and the two thermally-treating processesare not required. Consequently, the method of producing the hydrogenstorage container 3 according to the present invention is time-savingand labor-saving.

From the above descriptions, the thermally-conductive material and thegranular elastic material of the hydrogen storage composition are usedfor replacing the aluminum boxes of the conventional technology. The useof the granular elastic material can alleviate a deformation resultedfrom a volume expansion or shrinkage of the hydrogen storage material.The use of the thermally-conductive material can increase the thermalconduction efficacy of the hydrogen storage composition and alleviate adisplacement of granular elastic material relative to the hydrogenstorage material. Consequently, it facilitates the hydrogen storagecomposition to achieve an optimized packing density and the dischargedamount of hydrogen gas and the hydrogen desorption duration increase.Moreover, the addition of the granular elastic material can alleviatethe deformation (or strain) that is resulted from the volume expansionor shrinkage of the hydrogen storage material and limited by thethermally-conductive material. Since the deformation of the canisterbody is reduced, the durability and safety of the canister body areenhanced. Since the hydrogen storage composition is a mixture of pureseparable states, and the hydrogen storage material, the granularelastic material and the thermally-conductive material are separable byphysical classification, it facilitates the hydrogen storage compositionto be adjustable and reworked according to the practical requirements.Furthermore, the process of pouring the hydrogen storage material intoplural aluminum boxes, the process of placing the aluminum boxes intothe canister body and the two thermally-treating processes are notneeded, the method of producing the hydrogen storage container accordingto the present invention is cost-effective, material-saving,labor-saving and time-saving. In other words, the hydrogen storagecomposition and the method for producing the hydrogen storage containeraccording to the present invention are industrially valuable.

While the invention has been described in terms of what is presentlyconsidered to be the most practical and preferred embodiments, it is tobe understood that the invention needs not be limited to the disclosedembodiment. On the contrary, it is intended to cover variousmodifications and similar arrangements included within the spirit andscope of the appended claims which are to be accorded with the broadestinterpretation so as to encompass all such modifications and similarstructures.

What is claimed is:
 1. A hydrogen storage composition, comprising: a hydrogen storage material; a granular elastic material mixed with the hydrogen storage material and configured to alleviate a deformation that is resulted from a volume expansion or shrinkage of the hydrogen storage material; and a thermally-conductive material mixed with the hydrogen storage material and the granular elastic material and configured to conduct heat among the hydrogen storage material and alleviate a displacement of the granular elastic material relative to the hydrogen storage material, wherein each of the hydrogen storage material, the granular elastic material and the thermally-conductive material has the same physical and chemical properties as those before mixing and is removable from the hydrogen storage composition by sieving.
 2. The hydrogen storage composition according to claim 1, wherein the hydrogen storage composition comprises 1 to 15 weight parts of the thermally-conductive material and 1 to 35 weight parts of the granular elastic material, based on a total of 100 weight parts of the hydrogen storage material, the granular elastic material and the thermally-conductive material.
 3. The hydrogen storage composition according to claim 1, wherein the granular elastic material is an elastic resin, or a solid polymeric material selected from the group consisting of polyurethane, rubber, elastomer, poly (vinyl chloride), acrylonitrile-butadiene-styrene copolymer, high density polyethylene, low density polyethylene, polystyrene, polycarbonate, poly (methyl methacrylate), thermoplastic elastomer and polypropylene.
 4. The hydrogen storage composition according to claim 1, wherein the granular elastic material includes a solid polymeric material having a deformation ratio higher than or equal to the deformation ratio of the hydrogen storage material.
 5. The hydrogen storage composition according to claim 1, wherein the hydrogen storage material, the granular elastic material and the thermally-conductive material are separable by physical classification.
 6. The hydrogen storage composition according to claim 1, wherein the thermally-conductive material is carbon, copper, titanium, zinc, iron, vanadium, chromium, manganese, cobalt, nickel or aluminum.
 7. The hydrogen storage composition according to claim 1, wherein the thermally-conductive material has a length larger than a diameter of the granular elastic material, and the diameter of the granular elastic material is larger than a diameter of the hydrogen storage material.
 8. A hydrogen storage container, comprising: a canister body; and a hydrogen storage composition contained in the canister body, wherein the hydrogen storage composition comprises a hydrogen storage material; a granular elastic material mixed with the hydrogen storage material and configured to alleviate a deformation that is resulted from a volume expansion or shrinkage of the hydrogen storage material; and a thermally-conductive material mixed with the hydrogen storage material and the granular elastic material and configured to conduct heat among the hydrogen storage material and alleviate a displacement of the granular elastic material relative to the hydrogen storage material, wherein each of the hydrogen storage material, the granular elastic material and the thermally-conductive material has the same physical and chemical properties as those before mixing and is removable from the hydrogen storage composition by sieving.
 9. The hydrogen storage container according to claim 8, wherein the hydrogen storage composition comprises 1 to 15 weight parts of thermally-conductive material and 1 to 35 weight parts of the granular elastic material, based on a total of 100 weight parts of the hydrogen storage material, the granular elastic material and the thermally-conductive material.
 10. The hydrogen storage container according to claim 8, wherein the granular elastic material is an elastic resin, or a solid polymeric material selected from the group consisting of polyurethane, rubber, elastomers, poly (vinyl chloride), acrylonitrile-butadiene-styrene copolymer, high density polyethylene, low density polyethylene, polystyrene, polycarbonate, poly (methyl methacrylate), thermoplastic elastomer and polypropylene.
 11. The hydrogen storage container according to claim 8, wherein the granular elastic material includes a solid polymeric material having deformation ratio higher than or equal to the deformation ratio of the hydrogen storage material.
 12. The hydrogen storage container according to claim 8, wherein the hydrogen storage material, the granular elastic material and the thermally-conductive material are separable by physical classification.
 13. The hydrogen storage container according to claim 8, wherein the thermally-conductive material is carbon, copper, titanium, zinc, iron, vanadium, chromium, manganese, cobalt, nickel or aluminum.
 14. The hydrogen storage container according to claim 8 wherein the thermally-conductive material has a length larger than a diameter of the granular elastic material, and the diameter of the granular elastic material is larger than a diameter of the hydrogen storage material.
 15. A method for producing a hydrogen storage container, the method comprising steps of: (a) placing a hydrogen storage composition into a canister body, wherein the hydrogen storage composition comprises a hydrogen storage material, a granular elastic material mixed with the hydrogen storage material and configured to alleviate a deformation that is resulted from a volume expansion or shrinkage of the hydrogen storage material, and a thermally-conductive material mixed with the hydrogen storage material and the granular elastic material and configured to conduct heat among the hydrogen storage material and the canister body, and alleviate a displacement of the granular elastic material relative to the hydrogen storage material, wherein each of the hydrogen storage material, the granular elastic material and the thermally-conductive material has the same physical and chemical properties as those before mixing and is removable from the hydrogen storage composition by sieving; (b) creating a vacuum environment within the canister body, and recording a first weight of the canister body; (c) charging hydrogen gas into the canister body to activate the hydrogen the hydrogen storage material, and recording a second weight of the canister body; and (d) calculating a hydrogen storage amount according to the first weight and the second weight, and judging whether the hydrogen storage amount reaches a predetermined value, wherein if the hydrogen storage amount reaches the predetermined value, the hydrogen storage container is produced, wherein if the hydrogen storage amount does not reach the predetermined value, the steps (b), (c) and (d) are repeatedly done.
 16. The method according to claim 15, wherein in the step (a), the hydrogen storage composition comprises 1 to 15 weight parts of thermally-conductive material and 1 to 35 weight parts of the granular elastic material, based on a total of 100 weight parts of the hydrogen storage material, the granular elastic material and the thermally-conductive material.
 17. The method according to claim 15, wherein the hydrogen storage composition is prepared by steps of: mixing the thermally-conductive material and the granular elastic material in a pretreatment vessel; creating a vacuum environment within the pretreatment vessel; and adding the hydrogen storage material into the pretreatment vessel, so that the hydrogen storage composition is prepared.
 18. The method according to claim 15, wherein after the thermally-conductive material and the granular elastic material are mixed in the pretreatment vessel, the pretreatment vessel is sealed and placed in a constant temperature environment at 60° C. or higher, and a vacuum pump is used to create the vacuum environment within the pretreatment vessel.
 19. The method according to claim 15, wherein in the step (c), after the hydrogen storage composition is placed into a canister body, the canister body is sealed and placed in a constant temperature environment at 60° C. or higher, and a vacuum pump is used to create the vacuum environment within the canister body.
 20. The method according to claim 15, wherein the step of charging hydrogen gas into the canister body is performed by placing the canister body in a hydrogen supply system at 5° C. to 20° C. and charging pure hydrogen gas into the canister body for at least one hour. 